Strong Clustering of Faint Galaxies at Small Angular Scales
Abstract
The twopoint angular correlation function of galaxies, omega ( theta ), has been computed on equatorial fields observed with the Cerro Telolo InterAmerican Observatory 4 m prime focus, within a total area of 2.31 deg2. In the magnitude range 19 <= mR <= 21.5, corresponding to <z> ~ 0.35, we find an excess of power in omega ( theta ) at scales 2" <= theta <= 6" over what would be expected from an extrapolation of omega ( theta ) measured at larger theta . The significance of this excess is ~5 sigma . At larger scales, 6" < theta <= 24", the amplitude of omega ( theta ) is 1.6 times smaller than the standard nonevolutionary model. At these scales there is remarkable agreement between the present data and Infante & Pritchet (1995). At large angular scales (6" < theta <= 24") the data are best described by a model where clustering evolution in xi (r, z) has taken place. Strong luminosity evolution cannot be ruled out with the present data. At smaller scales, 2" <= theta <= 6", our data are formally fitted by models where epsilon = 2.4( Omega = 0.2, r0 = 5.1 h1 Mpc) or r0 = 7.3 h1 Mpc ( Omega = 0.2, epsilon = 0). If the mean redshift of our sample is 0.35, then our data show a clear detection of the scale (~19 h1 kpc) where the clustering evolution approaches a highly nonlinear regime, i.e., epsilon <= 0. The rate at which galaxies merge has been computed. If this rate is proportional to (1 + z)m, then m = 2.2 +/ 0.5.
 Publication:

The Astrophysical Journal
 Pub Date:
 October 1996
 DOI:
 10.1086/310274
 arXiv:
 arXiv:astroph/9608037
 Bibcode:
 1996ApJ...469L..85I
 Keywords:

 GALAXIES: EVOLUTION;
 GALAXIES: FORMATION;
 GALAXIES: INTERACTIONS;
 Astrophysics
 EPrint:
 10 pages, LaTeX text, 2 Postscript figures, To appear in ApJ Lett